For the past few weeks I have noticed a very odd Loose tin sound when I drive over bumps. They checked (Warrenty since these are BRAKE NEW Brake pads installed by them less than 1 month ago) the rear rotors, sanded them down and it disappeared for 1 day and came back the next day (COURSE IT RAINED THAT DAY SO perhaps the rain had caused it to disappear.. or was merely coincidental).

I figured out WHERE it is coming from. REAR DRIVER WHEEL.

I shake the rear driver wheel and it KNOCKS. The rims appears to be SOLID and TIGHTLY bolted on. It seems the sound comes from BEHIND the rotor..

I describe the sound as a Shopping Groccery cart where if you were to kick it.. the sound it would make...

Symptoms:

* Appears when you go over rough bumps (not speed bumps, and not pushing shocks down)

* STOPS when you apply brakes. (Brake OFF.. Loose Tin sound,Brakes ON.. Disappears completely).

I took 3 video's.

SAVE AS Because some are large

1. Video of my shaking the wheel - www.camarosource.ca/temp/100_8012.MOV (2.9M)

2. Video of my shaking the wheel - www.camarosource.ca/temp/100_8014.MOV (2.9M)

3. Video of me driving by over a bump in alley. You can CLEARLY hear it the SECOND time I drive forward (0.52secs - 0.53sec) - www.camarosource.ca/temp/100_8015.MOV (Large 17.6M)

I have taken it to 2 different shops.

They both claim that they could not get it to do it for them nor when they did road test. (Rediculous cause it does it for me the MOMENT the car moves).

THe last shop took apart the rear differential and said everything was perfectly fine. Both checked the brakes and they appear fine. The last one also checked the supension and tranny..

Remember the sound DISAPPEARS when you BRAKE so it seems to be related... HELP!

 

Are you missing the anti rattle clips for the rear pads? That night be it. When my car did that it was because my rear calipers were frozen.

 

Interesting! How would I tell? What do I look for? I can look under the car if you can tell me exactly what I am looking for.

Any way of diagnosing possible causes via driving conditions?

Thanks.

 

That sounds fairly serious, but unfortunately I have no ideas to help, however, the body and interior board is more of an appearance board, i'd post in the tech/general engine, more "mechanics" there, or even better, in the suspension forum, i'm pretty sure someone like RB or '83Crossfire would know it...

I couldn't get the larger video to work, only the smaller one, and that's a nasty noise when you shake the car on the ground, my suggestion would be to jack it up, put two jackstands under the axle (if you can...) and wiggle your panhard rod and LCAs, my first (completely ignorant) guess would be severly worn panhard rod bushings, or, actually, LCA bushings... no noise on up and down movement, but noise on side to side..... hmm, seriously, i'd copy the post to the suspension forum, I think i'd leave the brakes out of it though, just a guess.... (perhaps jack it up, take off the wheels and shake the caliper and rotor a bit, chances are your mechanic screwed something up....)


PS. Awesome looking car.

EDIT:
https://www.thirdgen.org/techbb2/sho...=under+car+pic
That thread has a mess of pictures, maybe someone could be kind enough to MSPAINT on which components you'd like to check....

 

Ugh. I just watched your video of you shaking the wheel and I doubt it's related to the brakes. I have no idea why it would stop when you get get on the brakes though.

 

The differential shop I took the car to said that movement (like 1/4" play back and forth) is COMPLETELY NORMAL.. Sorry but that seems like bull...

Anyone here please do an experiment.

1. Park car on FLAT surface
2. Put car into NEUTRAL
3. Emergency Brake OFF (in other words, make sure the car is secure and flat or it will coast away) :-)

4. Kneel to the side of your rear driver wheel.
5. Reach over the very TOP of the tire and grab a deep tread with your fingers.
6. HANK back and forth (towards the SIDE of the vehicle) (in otherwords, in line with the axle.. I want you to try and slide the axle back and forth)

Basically you're doing the EXACT same thing I am doing in video 1 (http://www.camarosource.ca/temp/100_8012.MOV)

Please tell me if that noise happens to you?

THANKS!

 

My 'Bird does have a slight side to side movement, but not quarter of an inch. Is this because the 10-bolt axle has the halfshafts held in place via C-clips within the differential?
Mind you I think I need the rear bearings replacing. I've got standard ones and seals. It remains to be seen if I need the "repair" bearing depending on halfshaft wear.

Mark.

 

It might be a simple thing like the dust shield for the disc brake rotors. Its thin metal and would give the tinny sound over bumps.
That was my problem and just needed to reweld the shield where it was loose, problem solved.. Its inboard of the rotor per picture.

 

Check the backing plate I had that same problem took me forever to finally find it I replaced and cheked so much crap before I found that was my problem

 

backing plate?

 

You have a disk setup right? It's that tin plate right behind the caliper. They are only tack welded in 2 spots and if one breaks off they start to rattle

 

Had the same rattle when 2 welds broke off.You can reach behind the wheel & pull on the dust shield.If it moves its loose.

 

It may be a crude outline it that is the backing plate....Ididn't have a welder so I just took mine off.

 

Yes, where you indicated is the location for the thin metal dust shield that is tack welded on.

 

Rear end Bearings? I think I remember reading if you have play in your axle it could be caused by this. Dunno about the breaking situation tho..